LawnByCounty

Lawn Care Guide for San Francisco County

San Francisco County, California

USDA SSURGO / PHZM

Data Story

About Lawn Care in San Francisco County, California

Ideal conditions for urban greenery

San Francisco County boasts a lawn difficulty score of 68.8, the highest among its neighbors and far easier than the 51.3 state average. In Hardiness Zone 10b, the consistent maritime climate is exceptionally kind to growing grass.

Cooler summers and steady moisture

With only 2 extreme heat days per year, your lawn rarely suffers from sun scorch. The 21.8 inches of annual rainfall is nearly double that of Southern California, though it still falls short of the 30-50 inches ideal for most lawns.

Overcoming urban soil limitations

While specific county-wide soil metrics are missing, urban lots in San Francisco often deal with compacted earth and limited drainage. Aerating your lawn once a year is a critical step to ensure water and air can reach the roots in this dense environment.

A rare year without drought

San Francisco experienced zero weeks of drought over the past year, making it a standout region for lush growth. You can maintain this advantage by using rain barrels to capture runoff for supplemental watering during the drier autumn months.

Green lawns all year long

Cool-season grasses like Kentucky Bluegrass or Fescue thrive in the city's constant 50-to-60 degree temperatures. Because frost is extremely rare here, you have a flexible window for seeding almost any time the weather is mild.

Lawn Difficulty Score

22/100
Easy
Rainfall55/100
Soil Quality0/100
Temperature1/100
Growing Season40/100
Drought0/100

Soil Summary

pH

N/A

Texture

N/A

Drainage

N/A

Organic Matter

N/A

View full soil details

Top Grass Fit for San Francisco County

Warm-season grasses are the general fit here

County soil and zone data are incomplete, so we show a category recommendation rather than a precise cultivar score for San Francisco County.

Why we ruled these out

  • Outsidepride Midnight Kentucky Bluegrass SeedUSDA zone 10b is above Outsidepride Midnight Kentucky Bluegrass Seed's effective range (2–8); not recommended for this county.
  • Scotts EZ Seed Patch & Repair Sun & ShadeUSDA zone 10b is above Scotts EZ Seed Patch & Repair Sun & Shade's effective range (2–9); not recommended for this county.

See our fit-score methodology for how survivability is determined.

Recommended Grasses

Warm-SeasonTransition Zone

Bermudagrass

Cynodon dactylon

Drought: 5/5Shade: 1/5
Suitability80%
View Seeds
Warm-Season

Seashore Paspalum

Paspalum vaginatum

Drought: 3/5Shade: 2/5
Suitability72%
View Seeds
Warm-Season

St. Augustinegrass

Stenotaphrum secundatum

Drought: 2/5Shade: 4/5
Suitability68%
View Seeds
Warm-Season

Dichondra

Dichondra repens

Drought: 2/5Shade: 4/5
Suitability68%
View Seeds

Best Grass Seed for San Francisco County

Zone 10bWarm-season grasses thrive here.

Find Seeds for Zone 10b

Climate Snapshot

Annual Precip

21.8"

Growing Degree Days

2,587.5

Base 50F

Last Spring Frost

-9999.0

First Fall Frost

-9999.0

Days Above 95F

2

Hardiness Zone

10b

Seeding Calendar — Zone 10B

J
F
M
A
M
J
J
A
S
O
N
D
Warm Seed (Best)
Warm Seed (OK)
Warm Seed (Best)
Warm Seed (OK)
Optimal (cool)
Acceptable (cool)
Optimal (warm)
Acceptable (warm)

Seasonal Lawn Care Checklist

Spring

  • Apply pre-emergent herbicide when soil reaches 55F
  • Begin mowing when grass reaches 3 inches
  • Start irrigation if rainfall is below 1 inch/week
  • Soil test every 2-3 years — adjust lime or sulfur as needed

Summer

  • Raise mowing height to reduce heat stress
  • Water deeply 1-2 times per week (1 inch total)
  • Avoid fertilizing cool-season grasses in peak heat
  • Scout for grubs and treat if >10 per sq ft

Fall

  • Overseed warm-season lawns if thinning
  • Apply fall fertilizer (highest N application for cool-season)
  • Continue mowing until growth stops
  • Rake or mulch leaves to prevent smothering

Winter

  • Apply pre-emergent for winter weeds
  • Service mower and sharpen blades
  • Plan spring soil amendments based on fall test
  • Overseed with ryegrass for winter color

Watering Deficit Calculator

50020,000 sq ft

Monthly Deficit

1.6"

inches of water

Monthly Water

4,920

gallons

Estimated Monthly Cost

$39.36

at $0.008/gallon average

Estimates based on 22" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.

Common Lawn Problems in San Francisco County

Drought Stress

With only 22 inches of annual rainfall, lawns in San Francisco County face significant drought stress. Consider drought-tolerant grass species and deep, infrequent watering.

Learn more about regional lawn challenges at The Lawn Report.

Lawn Care Advisory: San Francisco County

Lawn Verdict

San Francisco County is in USDA hardiness zone 10b, a warm zone well-suited to heat-tolerant grasses. with winter lows reaching around 35.0°F. and 2,587.5 growing degree days, sufficient for most common turfgrasses. Mild year-round temperatures create a relatively low-stress environment for turf. Moderate rainfall (21.8 inches) generally supports healthy lawns with minimal supplemental watering.

Seasonal Breakdown

Wait until after -9999.0 to seed or overseed; soil temperatures should consistently reach 50-55°F. Cool summers (July averages 59.2°F) reduce heat stress — maintain regular mowing and moderate watering. Aerate and overseed cool-season lawns by early fall, well before -9999.0; this is the best renovation window. Mild winters (January averages 52.3°F) allow year-round mowing for warm-season lawns and minimal dormancy.

Watering Guidance

Low annual precipitation (21.8 inches) makes irrigation essential for maintaining green turf through summer. The county is currently free of drought conditions. Cool summers reduce water demand; overwatering is a bigger risk than drought stress.

Regional Context

San Francisco County is close to the California average temperature, it is somewhat drier than the state average, the growing season is noticeably shorter than the state average, USDA zone 10b helps guide grass selection compared to neighboring counties.

Want detailed soil composition, drainage classes, and soil series data? View soil details on SoilByCounty.com

Frequently Asked Questions

What USDA hardiness zone is San Francisco County in?
San Francisco County is located in USDA hardiness zone 10b, based on the 2023 USDA Plant Hardiness Zone Map. This zone helps determine which grass species are most likely to thrive in the county's climate.
What is the best grass for San Francisco County?
Bermudagrass is the top recommendation for San Francisco County, with a match score of 80/100. It grows best in zones 7a–10b and requires 20–30 inches of water annually.
How much rainfall does San Francisco County get?
San Francisco County receives an average of 21.8 inches of precipitation per year, based on NOAA 30-year climate normals. This relatively low rainfall makes drought-tolerant grass species particularly important.

Data sourced from USDA SSURGO, NOAA Climate Normals (1991-2020), USDA Plant Hardiness Zone Map, and US Drought Monitor. Lawn difficulty scores and grass recommendations are estimates for informational purposes only.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor